Electrically powered systems for preparing beverages, in particular hot beverages such as tea or coffee, including such beverages that are prepared using portioned ingredients for instance contained in capsules or pods, have been developed and have become very popular, for use at home as well as out of home.
The numerous advantages of such systems have been widely recognized, in particular, their convenience of use, clean operations and better controlled quality of the brewed beverage delivered.
It is known to associate a radio frequency (RF) identifier to the capsule for the purpose of recognizing the capsule which is inserted in the device such as by a reader. Such identification allows changing particular operations, in the beverage producing device, in response to the detection of the identifier. For instance, brewing operations can be modified accordingly for adapting them to the type of capsule detected. For instance, brewing parameters, such as water temperature, the beverage volume or others, can be changed.
FR 2 912 124 relates to a portioned package for preparation of a beverage comprising two flexible walls connected by their seam and comprising an RFID tag for contactless reading which is positioned in a reinforced peripheral portion at the seam of the package. EP 1 890 271 relates to a method of controlling the dispensing of an infusion product with a container for a product dose and an RFID tag associated to a respective number of containers. GB 2 397 510 relates to a cartridge and machine for the preparation of beverage wherein each cartridge carries a code comprising a plurality of data bits which barcode is read by a beverage preparation machine upon insertion of the cartridge in the machine.
WO 2005/044067 relates to an apparatus enabling the traceability of the content of a receptacle and its origin wherein the receptacle comprises an optical or magnetic code containing information as to the content or origin of the receptacle which are read by an external reader, e.g., comprising a magnetic head. The code can be a metallic wire or ribbon containing recorded information in magnetic format.
Other systems has been developed which involve the use of optical recognition, e.g. of bar codes or other visual identifiers on capsules, as for example disclosed in WO02/28241 and GB 2 397 510.
Such prior art capsule recognition systems involve the use of complicated and/or expensive emitters and sensors. These sensing systems, particularly involving optical recognition, are likely to be exposed to interferences (insufficiently clean environment) and/or mis-positioning affecting the reliability of the sensing. Such delicate sensing devices are located in harsh environments, such as brewing unit, and thus exposed to high temperature and pressure likely to cause premature failure of such devices.
There is therefore still a need to simplify and/or reduce the costs involved with the sensing of capsules used in beverage preparation machines while providing a reliable sensing system.